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Well here it is.....I have been racing now for nine years straight and practing time in between races and I have the latest Smart performance kit in my 2010 450 yami with the special fluid in it. I love the way the forks feel and the suspension feels but there is just something missing that I just cant figure out.

I am missing one thing that has me stumped to the gills. At the regular MX tracks that I ride here in VA,NC,TN get pretty chewed up by the 2nd moto.

They get breaking bumps that are 7 and 8 inches deep the track gets rutted and the edges of the jumps get chewed up and pretty much your typical MX track.

With this kit in it and the fluid my bike does well above exceptional in the breaking bumps and chewed up edges of the jumps and on the landings of big jumps. I can hang on to the best of em from the starting gate to about three turns into the track and after that its .........see ya!

For some reason my bike seems to do well every where but in the turns. If the turn is rutted my front wheel all ways wants to climb up out of the rut.

If its a right hand turn that is banked or has a built up berm it wants swing wide and dont want to settle in at the rear as to where you could rail it.

What I mean is.....seems like the rear could soak up some more (squat) so when you got to the apex of the turn you could just gas it hard and shoot out.

There has to be something to do with the forks or suspension that is holing me back cause just this sunday down in NC at Windy Hill MX which is a sand track I was in 4 place till about the 2nd turn out of 23 riders and wound up finishing 17th.

It was the easiest track I have ever ridden. All though it was a fast track but the jumps were easy. I made all my time up in the straights cause I could fly through the worst bumps and dug out spots but the dam sharp left hand and right turns I seemed to be in slow motion,the bike wanted to swing wide all the time no matter how hard I tried tojerk the bike left or right.

Its like this at any of the MX tracks I go to on sharp left and right hand turns whether they are rutted or banked off camber or flat ( if rutted it wont stay in the rut).

I'm thinking it is in the rear by not wanting to squat down in the turn but some of the trouble could be in the forks. I was just wondering if I moved the spanner nut on the shock up the shock shaft a little if that would help me more by getting the bike to sink down some more when powering into a turn with the throttle on?

I'm just stumped on how I can get good starts but get passed by others in turns all the time. If I could just figure out how to get this bike to turn better and not sacrifice the way it handels the roug stuff.

My set up right now with the bike sprung for my weight is

Forks comp= 11 out (from all the way in)

Reb= 12 out (from all the way in)

Shock Low speed comp= 10 out

Reb= 15 out

High speed comp= from 1 and a half turn in or all the way out (depending on what the condition of the track is)

Usually for the High speed I will turn it out as the track gets rougher. If it gets real rough I will turn it all the way out.

One other thing I would like to add .......The bike seems to sit up tall making it hard to stand flat footed at the gate and for some reason my tail bone stay sore a lot ......from I guess the seat hitting me when going across breaking bumps. I would like to get this matter solved.

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Set your sags right and get your spring rates right. You are a bit heavy on rear spring. With 315mm of travel, you should be looking at about 34mm static (+-2mm) and 107mm rider sag.

You didn't mention the front but that would help a lot if you have it set correctly. With 310mm of travel you should be looking at about 43.5mm static (+-2mm) and 77.5mm rider sag. MXers tend to want to vary to the minus side of the sag numbers. I ride offroad and like mine as close as possible.

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The forks are riding to high due to the loaded midvalve of the DDT Had the same problem on 09 crf 450 . agreed on the rest of the stuff as is plush but bike wouldnt turn understeered . there must be some float in midvalve to get front end to settle in corners Loaded Midvalves with springs wont allow this . Been there done that sent it back trust me I wished it did work as was alot of work for nothing and the forks were quite plush .

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No, from the numbers you are giving the springs are actually WAY off. Way too heavy on rear for sure. I will be too heavy on front too but you haven't give those sag numbers yet. I don't care who did the work. If you weren't there for him to help you measure the sag , he was just guessing. Skill level has little to do with the correct spring rate. Damping is more for skill level.

Your rider sag on the rear is good but the static sag shows you are way heavy on the spring. You should be at about 34mm static and at the same rider sag as you are now.

My spring rates are right. When the bike was new it was way too stiff for me so I had Litz racing to do my work and he got all the measurements done which included my weight and skill level.

I want to make a correction on my rider sag and static sag. I went out to the truck and got my log book where I keep my suspensin settings.

My rider sag is 106mm and 46mm static sag

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well when i took the bike to him and he put this smart performance kit in he told me that the springs would be ok for my weight according to what the 2010 450 yamaha YZ had in it. Dave Johnson has the build sheet or at least I believe he does and said I had a good set up for which myself I think I do.

"Like I said" the bike is superb through all rough choppy stuff all breaking bumps and is outstanding even if you come up short on a jump,it will soak the whole hit up but just getting it to turn I believe is the key.

I dont know how to give you the sag on the forks cause I dont know how to do them but when i had Litz racing to put this kit in I was there when he set the sag for me cause i sat on the bike.

If you say the rear is way to heavy ......Then how much will I have to go down in a shock spring?

i figured since the bike was working well for me every where else that the turning issue could be adjusted somehow to improve without compromising so much on how it handles the rough stuff.

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Here is my take on things.First I would play with the sag and fork tube height to get a better balance from front to back. Personally I think 106mm is a bit much since the forks ride high in the stroke with the DDT.

There is also a good amount of free bleed in the shock (stock) that allows to much LS bleed that causes a chassis imbalance. This combination can have a effect that you described. Play with the sag and try and find the sweet spot. Its not etched in stone that you have to run certain sag no.

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Well here it is.....I have been racing now for nine years straight and practing time in between races and I have the latest Smart performance kit in my 2010 450 yami with the special fluid in it. I love the way the forks feel and the suspension feels but there is just something missing that I just cant figure out.

I am missing one thing that has me stumped to the gills. At the regular MX tracks that I ride here in VA,NC,TN get pretty chewed up by the 2nd moto.

They get breaking bumps that are 7 and 8 inches deep the track gets rutted and the edges of the jumps get chewed up and pretty much your typical MX track.

With this kit in it and the fluid my bike does well above exceptional in the breaking bumps and chewed up edges of the jumps and on the landings of big jumps. I can hang on to the best of em from the starting gate to about three turns into the track and after that its .........see ya!

For some reason my bike seems to do well every where but in the turns. If the turn is rutted my front wheel all ways wants to climb up out of the rut.

If its a right hand turn that is banked or has a built up berm it wants swing wide and dont want to settle in at the rear as to where you could rail it.

What I mean is.....seems like the rear could soak up some more (squat) so when you got to the apex of the turn you could just gas it hard and shoot out.

There has to be something to do with the forks or suspension that is holing me back cause just this sunday down in NC at Windy Hill MX which is a sand track I was in 4 place till about the 2nd turn out of 23 riders and wound up finishing 17th.

It was the easiest track I have ever ridden. All though it was a fast track but the jumps were easy. I made all my time up in the straights cause I could fly through the worst bumps and dug out spots but the dam sharp left hand and right turns I seemed to be in slow motion,the bike wanted to swing wide all the time no matter how hard I tried tojerk the bike left or right.

Its like this at any of the MX tracks I go to on sharp left and right hand turns whether they are rutted or banked off camber or flat ( if rutted it wont stay in the rut).

I'm thinking it is in the rear by not wanting to squat down in the turn but some of the trouble could be in the forks. I was just wondering if I moved the spanner nut on the shock up the shock shaft a little if that would help me more by getting the bike to sink down some more when powering into a turn with the throttle on?

I'm just stumped on how I can get good starts but get passed by others in turns all the time. If I could just figure out how to get this bike to turn better and not sacrifice the way it handels the roug stuff.

My set up right now with the bike sprung for my weight is

Forks comp= 11 out (from all the way in)

Reb= 12 out (from all the way in)

Shock Low speed comp= 10 out

Reb= 15 out

High speed comp= from 1 and a half turn in or all the way out (depending on what the condition of the track is)

Usually for the High speed I will turn it out as the track gets rougher. If it gets real rough I will turn it all the way out.

One other thing I would like to add .......The bike seems to sit up tall making it hard to stand flat footed at the gate and for some reason my tail bone stay sore a lot ......from I guess the seat hitting me when going across breaking bumps. I would like to get this matter solved.

Captain, the YZF450’s head angle could definitely be a little steeper for a fast MX rider, invest in some 20mm offset triple clamps and pull the forks up through the clamps to compensate. Two companies that offer 20mm are Applied and Ride, (The Ride’s are a little more stable because they are stiffer)

Dwight, skill level can have a lot to do with spring rate, especially with the fork for example: a fast rider that runs an oversize brake is a lot more likely to need stiffer fork spring than a slower rider.

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I just called and got off the phone with the man that done my suspension (Litz racing). i told him what I thought of the kit and how well the bike handled and took bumps and landings (everything I stated above).

I did tell him my biggest concern which was the turning issues and I gave him the sag #'s which were 106mm rider and 46 Static and just as Dwight staed above Steve (my suspension guy) said the rear spring was to heavy and that everything I said made complete since (which was the bike trying to climb out of the ruts and being lazy when turning) he said the static was too high and needed to come down.

Also he said the bushing and something else was probably needed replacing by now. Told me to bring it in and he would go through it and get it straightened out.

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Your problem is a function of dive, and that's related to chassis load and the hydraulics being able to bleed down in time.

The 2010-11 YZ450 uses a mid-valve stem with a bleed passage (by-pass) that is too small for the DDT. This has to be modified, (to match the 06-09) and we may not have released that specification at the time that LITZ Racing did the build.

Additionally, you may need to run the forks up in the clamps a bit further as well, allowing more weight transfer towards the front....assuming that the rear sag is within range.

Under and over steer is a critical consideration when setting up a bike, even more so for riders that use the front wheel to turn.

Don't worry, the fix is fairly simple. We'll start with the stem modification first, then follow this with some chassis changes if need be. You'll be surprised with the transformation.

Dave

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I got my bike back from Steve Litz yesterday and he said he updated my forks and opened up all the orifices. He also said he modified my shim stack on the shock as well. He was talking about a (V)shape on the shim stack,saying it now has a slimmer gap at the bottom I believe now.

Said this slimmer gap will take away that harshness feeling I had when riding. This harshness I had was making my tailbone sore.

I asked him that by updating my forks and opening up the orifices if that would make the forks too soft cause I like the way they felt as they were. He said they will feel even better than before. He said if I liked the way they felt before....That I will be really suprised how well they will feel now. He stated the bike will now dive a lot better now in the turns and I will be wheeling out now.

Said they will be even more smoother now than before and should really like they way they feel. He went down to a 5.4kg shock spring to where as I had a 5.6 (stock) spring on before. He said the bike was choppered out before which was making it difficult for me to turn and by reducing the spring rate and updating the forks that the front forks and the modification that he done to the shock will work together now. He showed me by pressing somwhere at the top of the seat by the gas tank. When he pressed down you could see the forks compress at the same time as the shock. You could see they were working together.

I asked him if the mods that he made would make the bike softer (like when landing from a big jump and when you land would it hit hard as if bottoming out) He said no.......That is where the clickers come in,.....said I may have to go in on the clickers some and stiffen it up compared to where I was running them at but overall it would be a better turning bike with a more smoother ride than before.

He said I would be suprised with the difference and will love it now. He replaced the seals and bushing in the forks and the bushings were half worn in the forks. I cant wait to try it out this sunday.

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Just a question Captainknobby, how will the bike be less choppered with a softer sprng rate? Are you running more preload on the softer spring?

I cant answer that question cause I dont really know. The reason for the softer spring was with the issue of the harshness I was having with my stock spring.

The stock was making it hard on my tailbone. Seemed like while riding...... the stiff suspension was the culprit of making my tailbone real sore at the end of the day and for or five days afterwards. He said by replacing the stock spring with a softer one would help this issue by making the rear softer along with the modification he done with the shim stack for the shock. With the rear spring he put on (The 5.4kg) would work more and better with the fork modification that he done. In other words......The forks and shock will work more together now.

Most of the work he done to the forks was going to help with the turning and the choppered feel.

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i dont really see a different spring will help much with the turning, a stiff spring will actually hold up higher once past the sag numbers...so its going to be more fork related.

That you are correct!..... As Dave stated above the modification to my forks was not out at the time my when my fork kit was put in.....so Litz done the modification and updated my forks per Dave's specs.

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just though while on topic and not having to start another thread, i have no idea how to adjust suspension and on my 2007 kx250f my bike always feels like it wants to ride strait through the berm and i cant hold it down, i need to tighten up my rear suspension because i know i am too heavy for the stock setting, can someone give me tips on what is what and how to adjust it to do something? i am braindead when it comes o suspension and dont have a manual for my bike . thanks

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I had the same problems with my YZ250 when I got my suspension back from Dave. I ended up running the compression way out on the forks. He suggested 14 out on comp, which worked great on bumps and jumps, but in order to get it to turn on anything other than sand I had to go 17-18 out. Went in 1-2 clicks on the fork rebound too. Soften the rear comp 2 clicks and it settled down quite a bit better, and it turns great now and feels like I'm riding on a cloud.